This invention relates generally to a new class of antibiotics and a method for producing them. More particularly, this invention pertains to the new and useful antibiotic designated as No. K-73A, and methods for producing it from the cultural broth of a newly isolated organism, Streptomyces tanashiensis K-73.
As a result of a continuous program of research for the production of new and useful antibiotics a new strain of bacteria which produces a new class of antibiotics has been isolated from a soil sample collected in Tokyo, Japan. This bacterial strain has been deposited with the Antibiotic Industrial Techniques Laboratory, of the Japanese Academy of Industrial Techniques, and has been given Acceptance No. 2399. This bacterial strain has also been deposited with the American Type Culture Collection in the United States, and has been given ATCC Acceptance No. 31,053.